Transmission slipping?

[bradly]

What does it mean by transmission slipping? My friend recently drove my trail, 2008 model and told me the transmission is slipping. I have no idea about this. Can anyone tell me about it? And is it really a serious issue?

[danish]

Transmission slipping is a serious problem actually. When the gear doesnt operate properly. Whenever you have difficulty in putting reverse, or changing your gears to top it means the transmission is slipping. Sometimes when you hear the grinding noise when trying to change the gear, it indicates transmission slipping.